Android Mobile UI Design
ModinMobileSTS/SlayTheAmethystModded
Designs and reviews Android screens with attention to touch ergonomics, adaptive layouts, accessibility, state handling and an implementation handoff.
Designs responsive interfaces starting from mobile screens with progressive enhancement for larger devices.
Install Mobile First Design
$ npx skills add secondsky/claude-skills --skill mobile-first-design -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install secondsky/claude-skills mobile-first-design --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/secondsky/claude-skills.git skills-src && mkdir -p .claude/skills && cp -r skills-src/plugins/mobile-first-design/skills/mobile-first-design .claude/skills/mobile-first-design && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "mobile-first-design" agent skill from https://github.com/secondsky/claude-skills/tree/main/plugins/mobile-first-design/skills/mobile-first-design into .claude/skills/mobile-first-design/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "mobile-first-design", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/secondsky/claude-skills/tree/main/plugins/mobile-first-design/skills/mobile-first-designType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add secondsky/claude-skills --skill mobile-first-design -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install secondsky/claude-skills mobile-first-design --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/secondsky/claude-skills.git skills-src && mkdir -p .agents/skills && cp -r skills-src/plugins/mobile-first-design/skills/mobile-first-design .agents/skills/mobile-first-design && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "mobile-first-design" agent skill from https://github.com/secondsky/claude-skills/tree/main/plugins/mobile-first-design/skills/mobile-first-design into .agents/skills/mobile-first-design/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "mobile-first-design", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add secondsky/claude-skills --skill mobile-first-design -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install secondsky/claude-skills mobile-first-design --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/secondsky/claude-skills.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/plugins/mobile-first-design/skills/mobile-first-design .cursor/skills/mobile-first-design && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "mobile-first-design" agent skill from https://github.com/secondsky/claude-skills/tree/main/plugins/mobile-first-design/skills/mobile-first-design into .cursor/skills/mobile-first-design/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "mobile-first-design", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/secondsky/claude-skills.git --path plugins/mobile-first-design/skills/mobile-first-design--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add secondsky/claude-skills --skill mobile-first-design -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install secondsky/claude-skills mobile-first-design --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/secondsky/claude-skills.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/plugins/mobile-first-design/skills/mobile-first-design .gemini/skills/mobile-first-design && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "mobile-first-design" agent skill from https://github.com/secondsky/claude-skills/tree/main/plugins/mobile-first-design/skills/mobile-first-design into .gemini/skills/mobile-first-design/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "mobile-first-design", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install secondsky/claude-skills mobile-first-designInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add secondsky/claude-skills --skill mobile-first-design -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/secondsky/claude-skills.git skills-src && mkdir -p .github/skills && cp -r skills-src/plugins/mobile-first-design/skills/mobile-first-design .github/skills/mobile-first-design && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "mobile-first-design" agent skill from https://github.com/secondsky/claude-skills/tree/main/plugins/mobile-first-design/skills/mobile-first-design into .github/skills/mobile-first-design/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "mobile-first-design", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add secondsky/claude-skills --skill mobile-first-design -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install secondsky/claude-skills mobile-first-design --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/secondsky/claude-skills.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/plugins/mobile-first-design/skills/mobile-first-design .opencode/skills/mobile-first-design && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "mobile-first-design" agent skill from https://github.com/secondsky/claude-skills/tree/main/plugins/mobile-first-design/skills/mobile-first-design into .opencode/skills/mobile-first-design/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "mobile-first-design", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
mobile-first-design- GitHub stars
- 227
- Token cost
- ~494 tokens
- SKILL.md length
- 92 words
- Files
- 1
- Skills in repo
- 169
- Repo updated
- First seen
- Licence
- MIT
At a glance
Designs responsive interfaces starting from mobile screens with progressive enhancement for larger devices.
- Building responsive websites
- SKILL.md covers Breakpoints, Mobile-First CSS, Touch-Friendly Design and Performance Requirements, plus 2 more sections
- Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
- Optimizing for mobile users
What it does
Mobile First Design is an agent skill from secondsky/claude-skills. Designs responsive interfaces starting from mobile screens with progressive enhancement for larger devices. Use when building responsive websites, optimizing for mobile users, or implementing adaptive layouts.
Its SKILL.md is about 490 tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.
It sits in Mobile, covering Mobile UI design and Responsive design. The repository describes itself as: Production-ready skills for Claude Code CLI - Cloudflare, React, Tailwind v4, and AI integrations. The licence is MIT.
When your agent uses it
- Building responsive websites
- Optimizing for mobile users
- Implementing adaptive layouts
Example prompts
- “Use the mobile-first-design skill to design responsive interfaces starting from mobile screens with progressive enhancement for larger devices”
- “/mobile-first-design”
What it can do on your machine
Read from SKILL.md and the folder at commit 8837836. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md (its code samples are css and html).
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Mobile First Design loads about 494 tokens when it runs. Until then it costs about 57 tokens; SKILL.md has 92 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
The full file from secondsky/claude-skills at commit 8837836, republished under its MIT licence (© secondsky). 92 words, ~494 tokens.
Download SKILL.mdSave it as
.claude/skills/mobile-first-design/SKILL.md (or your agent's skills folder).- name
- mobile-first-design
- description
- Designs responsive interfaces starting from mobile screens with progressive enhancement for larger devices. Use when building responsive websites, optimizing for mobile users, or implementing adaptive layouts.
- license
- MIT
Mobile-First Design
Design interfaces starting with mobile as the foundation, then enhance for larger screens.
Breakpoints
| Name | Width | Devices |
|---|---|---|
| Mobile | 320-480px | iPhone SE, small Android |
| Tablet | 481-768px | iPad mini |
| Desktop | 769-1024px | iPad Pro, laptops |
| Large | 1025px+ | Desktop monitors |
Mobile-First CSS
/* Base styles (mobile) */
.container {
padding: 1rem;
}
.nav {
display: none; /* Hidden on mobile */
}
.nav-toggle {
display: block; /* Hamburger visible */
}
/* Tablet and up */
@media (min-width: 768px) {
.container {
padding: 2rem;
max-width: 720px;
margin: 0 auto;
}
.nav {
display: flex;
}
.nav-toggle {
display: none;
}
}
/* Desktop */
@media (min-width: 1024px) {
.container {
max-width: 960px;
}
}Touch-Friendly Design
/* Minimum touch target: 48x48px */
.button {
min-height: 48px;
min-width: 48px;
padding: 12px 24px;
}
/* Adequate spacing */
.list-item {
padding: 16px;
margin-bottom: 8px;
}Performance Requirements
| Metric | Target |
|---|---|
| First Contentful Paint | <3s on 3G |
| JS bundle | <100KB gzipped |
| Total page weight | <500KB |
Progressive Enhancement
<!-- Layer 1: Semantic HTML (works without CSS/JS) -->
<nav>
<a href="/home">Home</a>
<a href="/about">About</a>
</nav>
<!-- Layer 2: CSS enhances appearance -->
<!-- Layer 3: JS adds interactivity -->Best Practices
- Start design at 320px width
- Use relative units (rem, %, vw)
- Test on real devices
- Optimize images for mobile
- Minimize JavaScript for initial load
- Ensure readable text without zooming
© secondsky, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
Just SKILL.md in plugins/mobile-first-design/skills/mobile-first-design of secondsky/claude-skills.
Open the folder on GitHubat commit 8837836
Compare with similar skills
Mobile First Design next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Mobile First Design this skillsecondsky/claude-skills | 227 | — | ~494 | Automated safety check: Pass | MIT | |
| Android Mobile UI DesignModinMobileSTS/SlayTheAmethystModded | 400 | — | ~1k | Automated safety check: Pass | Custom licence | |
| Mobile UX Optimizercuriositech/some_claude_skills | 243 | — | ~2.7k | Automated safety check: Notes | MIT | |
| Mobile Designaiskillstore/marketplace | 430 | 4 repos | ~2.3k | Automated safety check: Pass | None | |
| Convert MobileFerroxLabs/wayland | 608 | — | ~5.3k | Automated safety check: Pass | MIT | |
| Acarshub Design Languagesdr-enthusiasts/docker-acarshub | 117 | — | ~1.1k | Automated safety check: Pass | GPL-3.0 |
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Related
Categories
Questions about Mobile First Design
What does Mobile First Design do?
Designs responsive interfaces starting from mobile screens with progressive enhancement for larger devices. Mobile First Design is an agent skill from secondsky/claude-skills. Designs responsive interfaces starting from mobile screens with progressive enhancement for larger devices.
When should I use Mobile First Design?
Mobile First Design fits situations like: building responsive websites; optimizing for mobile users; implementing adaptive layouts.
How do I install Mobile First Design in Claude Code?
Run `npx skills add secondsky/claude-skills --skill mobile-first-design -a claude-code`. Or copy the skill folder (plugins/mobile-first-design/skills/mobile-first-design in secondsky/claude-skills) into .claude/skills/mobile-first-design in your project. Claude Code loads it when a task matches its description.
How do I install Mobile First Design in Codex?
Run `npx skills add secondsky/claude-skills --skill mobile-first-design -a codex`. Or copy the skill folder (plugins/mobile-first-design/skills/mobile-first-design in secondsky/claude-skills) into .agents/skills/mobile-first-design in your project. Codex loads it when a task matches its description.
Can I use Mobile First Design in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add secondsky/claude-skills --skill mobile-first-design -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/mobile-first-design, .gemini/skills/mobile-first-design, .github/skills/mobile-first-design and .opencode/skills/mobile-first-design in your project.
What does Mobile First Design need to run?
SKILL.md names no scripts, command-line tools or credentials: Mobile First Design is instructions for the agent only.
Does Mobile First Design access the network?
SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.
Is Mobile First Design safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does Mobile First Design use?
Mobile First Design is published under the MIT licence (declared in SKILL.md). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Mobile First Design use?
About 494 tokens (SKILL.md is roughly 2k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
What are the alternatives to Mobile First Design?
Skills that share tags, products or a category with Mobile First Design: Android Mobile UI Design (ModinMobileSTS/SlayTheAmethystModded, 400 stars), Mobile UX Optimizer (curiositech/some_claude_skills, 243 stars), Mobile Design (aiskillstore/marketplace, 430 stars) and Convert Mobile (FerroxLabs/wayland, 608 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Mobile First Design?
secondsky (a GitHub user) maintains it in secondsky/claude-skills, which has 227 GitHub stars. The repository holds 169 skills in this directory. The repository was last updated on September 28, 2026.
Source: secondsky/claude-skills on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.